Process of deodorizing lubricating oils



May l1, 1937. A. A. WELLS POCESS OF DEODORIZING LUBRICATING OILS Filed March 27, 1934 Ill QQ @NSW l s URN Patented May 11, 1937 UNITED srargs PROCESS F DEODORIZING LUBRICATING OILS Alfred A. Wells, Roselle Park, N. J., assignor t0 Standard Oil Development Company, a corporation of Delaware Application March 27,4

2 Claims.

This invention relates to a process of producing lubricating oils of improved odor and will be understood from the following description when read in conjunction with the drawing the sole figure of which is a diagrammatic side elevation partly in section of an apparatus appropriate for carrying out the invention.

Lubricating oils which have been treated with an adsorbent clay often develop a disagreeable odor. This is especially the case with lubricating oils and cylinder stocks which have been nished by percolation through coarse clay such as coarse fullers earth or Attapulgus clay. Such percolation is often carried out at temperatures ranging from 200-350 F. and higher. It is believed that this odor is caused by the action of the clay on the sulphur compounds, thereby forming I-IzS and similar compounds. I have found that the treatment of these oils with a small quantity of SO2 in the presence of moisture will destroy this odor. The necessary time of treating can be shortened by raising the temperature to from 100 F. to 200 F. and above. A treating temperature of 150 F. very often gives good practical results. Any small excess of SO2 can readily be removed by blowing with steam, air, inert gas, such as naturalgas, refinery gas, nitrogen, CO2, etc., which at the same time brightens the oil due to the removal of the water vapors present.

Instead of using SO2 gas, any compound such as, for example, sodium or potassium bi-sulphite, which contains a loosely bound SO2 group can be used.

Referring now to the drawing, the same will be 5 described in conjunction with the method of operating the apparatus shown. The lubricating oil from storage tank I is pumped through preheater 2 and percolatng filter tank 3. The tank is filled with coarse clay 4 and provided with 4U lagging 5 to prevent heat losses. The treated oil is then passed through heating or cooling coil 6 to adjust its temperature and is pumped into the deodorizing tank l. When sodium bi-sulphite solution is used, the same may be pumped from the storage tank (not shown) through line 3 directly into the oil line leaving coil 6. Tank l is also provided with lagging 9 to prevent heat loss and with a` steam or inert gas line I0 conm nected with line Il for the introduction of SO2. UU The steam and SO2 are discharged into tank 'i through the spray i2. The treated oil is removed through bottom line I3, cooler I4 into the finished oil tank i5. The steam and gas leave tank i through overhead line It and steam condenser I1. A receiver l0 for any condensate, vent line l0 and vacuum pump are provided as shown.

The following examples will illustrate my invention: A cylinder oil which had been acid 1934, serial No. 717,541

treated and neutralized in the ordinary way was percolated through Attapulgus clay at a temperature of Z50-300 F. The oil coming from the percclating unit was cooled to 150 F. and then blown with steam for a short period. SO2 gas was then bubbled into the oil until a slight odor of SO2 could be detected. The SO2 supply was then shut 01T and the oil blown with air at 150 F. until the odor of SO2 had disappeared. The disagreeable odor of the original percolatecl oil was largely removed.

In another experiment the sample of oil which had previously been percolated at a temperature above 250 F. and which had a disagreeable odor was heated to 150 F. while at the same time a small amount of steam was blown through the oil. A solution or" sodium bi-sulphite was then added to the oil in the ratio of 0.35 gram of sodium bi-sulphite to a liter of oil and agitated with air for a brief period. The oil was then blown with steam at approximately 150 F. until the odor of sodium bi-sulphite had disappeared. The resulting oil was sweet in odor.

Still in another experiment the sample of oil which had been treated with SO2, as in the iirst example, was blown with nitrogen under a slight vacuum at a temperature of 200 F. to remove the traces of SO2. This sample had a particularly good odor.

In the following claims the term lubricating cil is meant to designate both lubricating oils and cylinder oils, whether obtained by overhead distillation or as residual stocks.

My process may be modified in various ways. The blowing with air or steam or inert gas may be carried out in atmospheric pressure or under vacuum. Other changes and modiications will be apparent to those skilled in the art. Therefore, my invention is not to be limited by the examples given ior illustration but only by the following claims, in which it is my intention to claim all novelty inherent in the invention.

What I claim is:

l. An improved process for refining mineral lubricating oils and removing objectionable odors therefrom, comprising the separate steps of treating the oil with clay at a temperature of the order of 200 F. and higher, separating the clay and then agitating the oil with moist sulfur dioxide at A a temperature below 200 F. and then removing any excess thereof.

2. A process according to claim 1 in which the clay treating step is accomplished at a temperature within the range from about 200 to 350 F., and treatment with moist sulfur dioxide at a lower temperature range within from about 100 to 200 F.

ALFRED A. WELLS. 

